----, 2d vol. 2d edition do. - - - - - - - - - - Jan. 1833. ----, 3d vol. 1st edition do. - - - - - - - - - - May 1833. ----, New edition (called the 3d) of the whole work in 4 vols. 12mo. - - - - - - - - - - - - - - - - - - - May 1834. ----, 4th edition, 4 vols. 12mo. - - - - - - - - - June 1835. ----, 5th edition, do. do. - - - - - - - - - - - - Mar. 1837. Elements, 1st edition in one vol. - - - - - - - - July 1838. Principles, 6th edition, 3 vols. 12mo. - - - - - - June 1840. Elements, 2d edition in 2 vols. 12mo. - - - - - - July 1841. Principles, 7th edition in one vol. 8vo. - - - - - Feb. 1847. ----, 8th edition, now published in one vol. 8vo. - May 1850. Manual of Elementary Geology (or "Elements," 3d edition), now published in one vol. 8vo. - - - - - - - - - - - - Jan. 1851. _Works by Sir Charles Lyell._ I. TRAVELS IN NORTH AMERICA,--1841-2. With Geological Observations on the United States, Canada, and Nova Scotia. With large coloured geological Map and Plates. 2 vols. post 8vo. 21_s._ II. A SECOND VISIT TO THE UNITED STATES,--1845-6. _Second Edition._ 2 vols. post 8vo. 18_s._ III. PRINCIPLES OF GEOLOGY; or the Modern Changes of the Earth and its Inhabitants considered, as illustrative of Geology. _Eighth Edition, thoroughly revised._ With Maps, Plates, and Woodcuts. 8vo. 18_s._ IV. A MANUAL OF ELEMENTARY GEOLOGY; or the ANCIENT CHANGES of the Earth and its Inhabitants, as illustrated by Geological Monuments. Fourth Edition. _Thoroughly revised._ With 531 Woodcuts and Plates. 8vo. 12_s._ MANUAL OF ELEMENTARY GEOLOGY. CHAPTER I. ON THE DIFFERENT CLASSES OF ROCKS. Geology defined--Successive formation of the earth's crust--Classification of rocks according to their origin and age--Aqueous rocks--Their stratification and imbedded fossils--Volcanic rocks, with and without cones and craters--Plutonic rocks, and their relation to the volcanic--Metamorphic rocks and their probable origin--The term primitive, why erroneously applied to the crystalline formations--Leading division of the work.